Simulação do craqueamento catalítico do gasóleo no reator de leite fixo utilizando um modelo cinético 4-LUMP.

Abstract

The catalytic cracking is an important and lucrative process of petroleum refining. Its objective is to increase the production of gasoline and it is the process more used in the world, as the demand of gasoline increased considerably in relation to the combustible oils. The reaction of the catalytic cracking of the gasoil using a kinetic 4-lumps model in a fixed bed reactor has been studied in this work. The model considered the deactivation of the activity of the catalyst as function of the rate of deposited coke, which is the main source of the catalytic deactivation considered. Using the kinetic constants, previously published in the literature, in the model the results of the following products were presented: the gasoline, the gases (C1-C4) and the coke, which were obtained by of simulations of the catalytic cracking reaction of the gasoil, for the temperature range of 482,2 °C to 615,5 °C. The influence of the ratio among the length of the reactor (L) and the speed (V) with which the fluid crosses the catalytic bed was also studied. To solve the model numericaly using the reactor of fixed bed, at first, a mathematical model of the reactor was developed from the fundamental equations (mass and energy balance) that describe the process. Soon after, a computacional program was developed using the numerical method of the orthogonal collocation to replace the differential partial equations system by algebric equations system. It was obtained by the method BDF (Backward Differential Formulates). The constituted program allowed simulating the reaction of the catalytic cracking of the gasoil. This program serves as a tool to define an operational policy of the reactor of fixed bed in relation to the control of the deactivation of the catalyst.